Problem: Which of these numbers is composite? ${13,\ 23,\ 47,\ 53,\ 96}$
Explanation: A composite number is a number that has more than two factors (including 1 and itself). 13, 23, 47, and 53 each have only two factors. The factors of 96 are 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, and 96. Thus, 96 is the composite number.